Rotary fluid dispensing mechanism for cleaning electrical contacts



p 1955 M. BROWN 2,719,204

ROTARY FLUID DISPENSING MECHANISM FOR CLEANING ELECTRICAL CONTACTS Filed Dec. 31, 1953 2 Sheets-Sheet 1 INVENTOR fl/Ef/l Y Z POM/AK ATTORN EY Sept. 27, 1955 M. BROWN ROTARY FLUID DISPENSING MECHANISM FOR CLEANING ELECTRICAL CONTACTS 2 Sheets-Sheet 2 Filed Dec. 31, 1955 INVENTOR ATTORNEY United States PatentO ROTARY FLUID DISPENSING MECHANISM FOR CLEANING ELECTRICAL CONTACTS Murray Brown, Brooklyn, N. Y.

Application December 31, 1953, Serial No. 401,585

2 Claims. (Cl. 200-166) This invention relates to a mechanism for applying fluid, such as cleaning fluid, through a hollow shaft to points disposed in spaced relation to said shaft.

In the conventional construction of television sets, the rotatable shafts for operating the set protrude through a front panel and are adapted to be secured exteriorly of the set to a finger operated knob. These rotatable shafts, interiorly of the front panel of the television set, are provided with mechanism adapted to engage individual contact points, or a continuous wire potentiometer, or other similar electrical contact mechanism, circumferentially disposed about said shafts.

Furthermore, some of the shafts protruding through the front panel of conventionally constructed television sets are of a dual type, namely a split shaft adapted to be coupled or uncoupled, adapted to independently operate selective electrical units.

It is an object of this invention to clean the electrical contact points disposed interiorly of the television set and circumferentially of the co-acting rotatable shaft.

It is another object of this invention to clean electrical contact points disposed interiorly of the television set and about a dual coupleable shaft.

These and other objects of this invention will become apparent upon reading the following disclosure taken in conjunction with the accompanying drawing in which:

Fig. l is a side view of an electrical potentiometer disposed through a television front panel, said panel being shown dotted outline,

Fig. 2 is a rear view of the potentiometer of Fig. 1 and taken on line 2-2 of Fig. 1,

Fig. 3 is a section view taken on line 33 of Fig. 2,

Fig. 4 is a schematic view showing the manner of applying cleaning fluid to a plurality of potentiometers circumferentially disposed about a single rotatable shaft,

Fig. 5 is a rear view of an electrical circular switch having a plurality of electrical slide contacts disposed in an arc about a rotatable shaft provided with a knife contact blade adapted to engage selectively said slide contacts,

Fig. 6 is a view taken on line 66 of Fig. 5,

Figure 6a is a perspective view of a nib for directing a stream of fluid.

Fig. 7 is a section view showing a pair of potentiometers adapted to be operated independently of one another by means of a dual shaft,

Fig. 8 is a rear view of the potentiometer of Fig. 7 and taken on line 88 of Fig. 7,

Fig. 9 is a detailed section view of the coupling mechanism of the shaft showing a coupled shaft,

Fig. 10 is a view similar to Fig. 9 showing the shaft in uncoupled position,

Fig. 11 is a perspective view of a nib having an aperture adjacent the closed end for directing a stream of fluid,

Fig. 12 is a detailed view of the mechanism for engaging and disengaging the selectable front switch upon uncoupling or coupling respectively the couple mechalllSIIl.

Referring to the Figs. 3, 6, 7, 9 and 10 the objective of this invention is obtained by providing the solid rotatable shaft 1 with an axially disposed borehole 2 and means associated with said borehole 2 for directing cleaning fluid flowing therethrough to electrical contact points disposed about the shaft 1.

Turning to Figs. 1 to 3, a potentiometer 3 is provided with a rotatable shaft 1, disposed through a panel 4, for example, in a television set. The shaft 1 is provided at the end protruding through the panel 4 with a finger operated knob 5 secured to the shaft 1 by means of a set-screw 6. The potentiometer is secured fixedly to the panel 4 by means of an externally threaded collar 7 or by other conventional means.

The potentiometer 3 is of conventional manufacture and is provided with an annular housing 8 made from insulating material and with a circular winding 9 disposed within the housing. A plurality of conduit wires 10 are connected to the winding circuit for tuning or otherwise effecting the electrical properties of the circuit.

According to the improvement invention of Figs. 1 to 3, the shaft 1 which is provided with borehole 2 is further provided with a hollow pipe elbow 11. The elbow 11 has screw threaded projection 12 on one end and is threaded into the borehole 2 interiorly of the panel 4. A hollow nib 13, closed at one end is preferably made of plastic, and inserted on the free end of the elbow 11. The nib 13 is provided with an aperture 14 disposed in such a manner that a stream of cleaning fluid, for example, carbon tetrachloride, may be forced by a pressure operated device 15 through the aperture 14 as a fine stream directed at the points of contact of winding 9 and the sliding contact point 16 coacting therewith. The contact point 16 is secured by conventional means to an insulating disc 17, said disc 17 being provided with a flange piece 18 adapted to arrest rotational movement upon abutting stop lug 19.

As shown in Fig. 4, a plurality of potentiometers 3 are disposed about a shaft 20. In this modification of the invention the bore-hole 21 does not extend throughout the shaft but terminates in spaced relation to the inner end of shaft 20.

In place of an elbow the shaft 20 is provided with screw threaded tap holes communicating with borehole 21 and disposed at right angles thereto. A metal nipple 22 having a screw threaded end is screwed in these tap holes and a nib 13 is disposed over each of the nipples.

As shown in Figs. 5 and 6, an electrical circular contact switch 23 may be used in lieu of a potentiometer 3 and a ball bearing detent 24 may be secured to shaft 1. In the modification of Figs. 5 and 6 the stream of cleaning fluid from aperture 14 (Fig. 6) is directed against the individual sliding contact points 24.

Turning to Figs. 7 to 12, another embodiment of this invention is illustrated. In this embodiment a split shaft having means for coupling is employed. The shaft generally shown by the numeral 25 (Fig. 7) may therefore operate rheostat 26 or 27 as selectively desired and consists of two shaft sections, namely a front slidable shaft section 28 and rear non-slidable shaft section 29. A borehole is axially drilled through both sections 28 and 29 and a pipe elbow 11 having a screwed threaded extension 12 is secured in the screw end of the borehole. The angle of bend in the elbow 11 is selected so that the stream of cleaning fluid is directed against the points of sliding contacts, since it is these points that become fouled and need cleaning from time to time, presently necessitating in the absence of this invention, a removal of the television chassis out of its cabinet.

As shown in detailed Figs. 9 and 10, shaft section 29 is regularly grooved about its coupling end with a plurality of grooves 30. The shaft section 28 is provided with an extension of narrow diameter 31 adapted to seat into a corresponding cavity in the coupling end of shaft section 29. A collar 32 is fixedly disposed around the shaft section 28 by means of a set screw 33. This collar is provided with a plurality of spaced apart splines 34 adapted to register with and engage the grooves 30. Clearly, movement of slidable shaft section 28 toward rheostat 26 causes a coupling with shaft section 29 so that rotation of shaft section 28 also rotates shaft section 29.

In order to operatively engage rheostat 26 the shaft section 28 is provided with a plurality of external splines 35 (Fig. 12) which are adapted to engage the plural grooves of disc 36. Obviously, pulling the knob (Fig. 7) causes the splines 35 to operatively engage disc 36 and to effect an uncoupling with shaft section 29.

A nipple 22 is secured to shaft section 28 and an elbow 11 to the end of shaft section 29, so that removal of knob 5 and application of pressurized cleaning fluid through the borehole of the coupled shaft 25 effects a cleaning of rheostat 26 and 27.

This invention has been disclosed and illustrated by many embodiments but other obvious embodiments are all intended to be covered by the claims herein.

I claim:

1. An electrical self-cleaning switch having circumferentially disposed contact points and having a rotatable shaft comprising said shaft having a bore-hole therethrough a hollow elbow removably and angularly secured to the end of the shaft adjacent the contact points, and an apertured nib disposed over the elbow whereby pressurized cleaning fluid is selectively forced through the bore-hole, elbow and the aperture of the nib as a stream against said electrical contact points circumferentially disposed about the shaft whereby said contact points may be cleaned while the switch is in operation.

2. The apparatus of claim 1 having a plurality of switches disposed about the shaft and having a plurality of hollow conduits communicating with the bore-hole, each conduit being disposed adjacent a switch and provided with an apertured nib whereby cleaning fluid forced through said conduits cleans the contact points of said switches while said switches are in continuous rotational operation.

References Cited in the file of this patent UNITED STATES PATENTS 

